Synopsis
Distinguish early-pregnancy bleeding with ongoing viability from missed, incomplete and complete miscarriage using safe ultrasound criteria while continuing to exclude ectopic pregnancy.
- Threatened miscarriage means vaginal bleeding with a confirmed intrauterine pregnancy that remains viable; the cervix is usually closed and many pregnancies continue.
- Missed miscarriage means an intrauterine pregnancy has stopped developing but pregnancy tissue remains, often with little bleeding and a closed cervix.
- Incomplete miscarriage means some intrauterine pregnancy tissue has passed but tissue remains, usually with continuing bleeding, cramping and an open cervix.
Key red flags
A positive pregnancy test with unilateral pain, shoulder-tip pain, collapse or an empty uterus may be ectopic pregnancy even if tissue or clots have passed.
Investigation priorities
Confirm location, viability, retained tissue and adnexal or free-fluid findings.
Management branches
A patient presents with pain or bleeding in early pregnancy.
- Assess haemodynamics, bleeding, pain, ectopic and infection features and escalate shock, peritonism, sepsis or uncontrolled bleeding immediately.
- Obtain pregnancy testing, expert transvaginal ultrasound and targeted bloods, adding consented speculum examination where it answers bleeding or tissue questions.
Key medicines
Micronised vaginal progesterone for threatened miscarriageInsert 400 mg vaginally twice daily when scan confirms an intrauterine pregnancy, current bleeding is present and at least one previous miscarriage occurred; if fetal heartbeat is confirmed continue to 16 completed weeks.